Schema migration Memes

You know that sinking feeling when you fire off an ALTER TABLE command in production and then realize you never checked the table size? Yeah, we've all been there. First minute you're confident—just a quick schema change, no big deal. By 15 minutes you're sweating, refreshing your monitoring dashboard. An hour in? You're having an existential crisis while the table lock holds your entire application hostage and your phone starts buzzing with Slack notifications. Pro tip: always run SELECT COUNT(*) FROM table or check the table size before altering. Better yet, use tools like pt-online-schema-change or gh-ost for large tables. Your future self (and your users) will thank you when they're not staring at a locked database for the next 3 hours.

Database Administrator's definition of "smooth migration" = server is on fire but at least one user can still log in. The rest of the team doesn't need to know about the flaming wreckage of tables and indexes above. Just smile and say "yasss" when asked if everything's fine. We'll fix it in post-production.